/Engine/Plugins/MeshPainting/Source/MeshPaintingToolset/Public/MeshPaintHelpers.h
Given arguments for an action, and an action - retrieves influences vertices and applies Action to them
bool ApplyPerVertexPaintAction ( [FPerVertexPaintActionArgs](API\Editor\MeshPaint\FPerVertexPaintActionArgs) & InArgs, FPerVertexPaintAction Action )